A cluster randomised controlled trial of family-based Zero-time Exercise mobile messages on physical activity, family interaction and happiness in Chinese adults in Hong Kong

Abstract

Purpose: Zero-time Exercise, an integration of simple strength- and stamina-enhancing physical activity into daily life, can be done anytime, anywhere and by anyone. We evaluated whether family-based Zero-time Exercise mobile messaging can further enhance the effect of a brief holistic health intervention on physical activity, family interaction and well-being (perceived health, happiness and harmony) in Chinese adults in Hong Kong. Methods: In a cluster, randomized controlled trial on 240 participants (83% female, 65% and age <40 years) from 12 institutions (primary schools and units/offices of The Boy's & Girls' Clubs Association of Hong Kong) were randomized into either a Physical activity (PA) group (n=117 from 5 institutions) or Healthy eating control message (Control) group (n=123 from 7 institutions). Both groups received the same holistic health intervention (two 2-hour sessions) including Zero-time Exercise and healthy eating information, but different daily mobile messages for 3 months. The PA group received about 90 familybased Zero-time Exercise messages, guided by the Health Action Process Approach. The messages encouraged participants to (i) use ZTEx to enhance participants' physical activity and well-being and (ii) exercise with family members to enhance family interaction. The Control group received about 90 healthy eating messages. Results: Both PA and Control groups reported significant increases in physical activity, ZTEx, family interaction and well-being at the 1-month and 3-month follow-up. The PA group showed significantly greater increases in moderate physical activity by 0.8 day in a week (95% confidence interval [CI] = 0.1, 1.4) at 3-month follow-up; and significantly greater increases in ZTEx by 0.3 score (out of 5) (95% CI = 0.1, 0.5), engaging family members in ZTEx by 0.2 score (out of 5) (95% CI = 0.1, 0.4), personal happiness by 0.3 score (out of 10) (95% CI =0.1, 0.5) and family happiness by 0.3 score (out of 10) (95%CI = 0.1, 0.5) during the 3-month study period, compared to the Control group. The effect size was small (Cohen's d: 0.19, 0.40). Conclusions: We found good evidence that daily Zero-time Exercise messaging enhanced participants' physical activity, family interaction, and personal and family happiness. Further trials on such approach are warranted.